4/5/2012 10:25 AM PDT

The Atlanta Police Department says it's launched an internal investigation .... after Perry publicly accused two officers of racially profiling him during a traffic stop earlier this week.

Perry says he was leaving his ATL studio ... when he made a left turn from the right lane to ensure he wasn't being followed. Tyler explains, "It’s a safety precaution that my security team taught me."

But Tyler was pulled over by police for the illegal turn ... and claims he was harassed by two "hostile" white officers until a black cop arrived to the scene and recognized him.

On his Facebook page, Perry says the black cop "immediately took both officers to the back of my car and spoke to them in a hushed tone. After that, one of the officers stayed near his car while one came back, very apologetic. I said all of that to say this: do you see how quickly this could have turned for the worse?"

Tyler then wrote, "RACIAL PROFILING SHOULD BE A HATE CRIME INVESTIGATED BY THE FBI!!!"

For the record -- Tyler Perry did NOT get a ticket.

Reps for the ATL PD say it's looking into "whether any departmental policies or procedures were violated during the stop.”